VDB-416223 · Submit #954247 · CVE-2026-108566

InstantSoft icms2 up to 2.18.2 Private Message index.tpl.php index nickname cross site scripting

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
3.2	$0-$5k	1.05+

Summaryinfo

A vulnerability has been found in InstantSoft icms2 up to 2.18.2 and classified as problematic. Impacted is the function index of the file templates/default/controllers/messages/index.tpl.php of the component Private Message Handler. Performing a manipulation of the argument nickname results in cross site scripting. This vulnerability was named CVE-2026-108566. The attack may be initiated remotely. In addition, an exploit is available. It is recommended to apply a patch to fix this issue.

Detailsinfo

A vulnerability classified as problematic has been found in InstantSoft icms2 up to 2.18.2. This affects the function index of the file templates/default/controllers/messages/index.tpl.php of the component Private Message Handler. The manipulation of the argument nickname with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity.

This vulnerability is uniquely identified as CVE-2026-108566. The exploitability is told to be easy. It is possible to initiate the attack remotely. It demands that the victim is doing some kind of user interaction. Technical details and a public exploit are known. The attack technique deployed by this issue is T1059.007 according to MITRE ATT&CK.

It is declared as proof-of-concept. By approaching the search of inurl:templates/default/controllers/messages/index.tpl.php it is possible to find vulnerable targets with Google Hacking.

Applying the patch 3a1ec8fcb073a46d06a2ab83bc2bf68225834281 is able to eliminate this problem. The bugfix is ready for download at github.com.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Content Management System

Vendor

InstantSoft

Name

icms2

Version

License

open-source

Website

Product: https://github.com/instantsoft/icms2/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.2

VulDB Base Score: 3.5
VulDB Temp Score: 3.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Google Hack: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔒

Patch: 3a1ec8fcb073a46d06a2ab83bc2bf68225834281

Timelineinfo

10/10/2026 Advisory disclosed
10/10/2026 +0 days VulDB entry created
10/10/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Status: Confirmed

CVE: CVE-2026-108566 (🔒)
GCVE (CVE): GCVE-0-2026-108566
GCVE (VulDB): GCVE-100-416223
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 10/10/2026 17:09
Changes: 10/10/2026 17:09 (58)
Complete: 🔍
Submitter: EVIL0RD
Cache ID: 216::103

Submitinfo

Accepted

Submit #954247: InstantCMS InstantCMS icms2 2.18.2 Cross-Site Scripting (XSS) (by EVIL0RD)